BTW, another advice. Don't allow to modify your players directly, that can lead to HibernateErrors such us "Don't change the reference to a collection...". Instead of setPlayers(), add methods for addPlayer() and removePlayer()

There's no reason to make the association bidirectional. And anyway, in a bidirectional association, only one of the sides must have the mappedBy attribute, since it means: "go see the mapping for the association at the other side".
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JB NizetSep 27 '12 at 13:13